For instance, when carrying out maintenance on various apparatuses such as a diesel engine, a maintenance monitor device is used to monitor the operation state of the apparatus in real time. The maintenance monitor device displays measurement values or the like that indicate the operation state of the apparatus on a monitor screen in real time.
FIG. 5 is a diagram of a monitor screen displayed by a conventional monitor device.
On the conventional monitor screen 100, a graph with the x-axis indicating time is displayed. On the graph, displayed are numerical data of a plurality of display items, such as the engine rotation speed (a), the acceleration opening degree (b), the cooling water temperature (c), the boost pressure (d), the intake temperature (e), the rail pressure (f), and the total fuel injection amount (g), associated with the graph axes.
Further, as illustrated in FIG. 5, scales, names, and units are displayed on the y-axis of the graph, corresponding to the plurality of display items (a) to (g) described above.